![]() Lombardi AJ revealed that the pulsed AC DBD actuation could increase the integrated lift of an oscillating airfoil by 12% and reduce the maximum nose-down moment by 60%. Paper numerically revealed that F + = 50 is the most effective for delaying dynamic stall onset, F + = 0.5 is best for enhancing aerodynamic forces during full stall, and F + = 6 is best for promoting reattachment. It is found that the flow control effect can be maximized by adopting the low nondimensional actuation frequency. The influence of NS-DBD actuation parameters on the dynamic stall control effect was investigated with the freestream velocity U ∞ = 50 m/s in paper. Yu HC and Zheng JG found that NS DBD achieves surprising success in enhancing lift and reducing aerodynamic hysteresis at Re = 7.5 × 10 5, whereas AC DBD nearly has no effect on the flow. found that the separated flow can be reattached under actuation during the down phase of an oscillating NACA0015 airfoil. found that NS DBD actuation could improve stall state and promote the early recovery of wing’s upper surface pressure. found that the pulsed AC DBD could improve the lift hysteresis loop at the optimal actuation frequency of F + = 0.5 at the free-stream velocity 10 m/s-50 m/s. DBD plasma actuation is expected to provide a new control method for improving the rotor’s performance during dynamic stall. This typical flow condition is within the controllable range of DBD plasma actuation. For helicopters, the typical flow velocity over the retreating blades is on the order of 100 m/s ( Ma = 0.3) and the Reynolds number is on the order of 10 6. summarized the airfoil’s dynamic stall control by plasma actuation in recent years. The literature in recent years has an increasing trend, indicating that dynamic stall control by plasma actuation has begun to attract more attention. Dynamic stall control by DBD plasma actuation started about 15 years ago. įlow separation control by DBD plasma actuation is mainly focused on static airfoils while the dynamic stall control of oscillating airfoils has not been widely studied. The research progress of DBD plasma actuation in flow control was summarized in Literature. PSJ and SAD actuations are mostly used for shock wave control in the supersonic fields, while the low-speed flow separation is usually controlled by plasma of AC DBD and pulsed nanosecond surface (NS) DBD. Common plasma actuation methods include plasma synthetic jets (PSJ), surface arc discharge (SAD) and dielectric barrier discharge (DBD). Plasma actuation is prone to cause rapid and controllable broadband pneumatic actuation, and has a potential in dynamic stall control. Therefore, the study of dynamic stall control is of great engineering significance. For helicopters, the most direct impact of the blade’s dynamic stall is to limit its maximum forward speed. Dynamic stall can cause the wing’s flutter with a sharp drop in lift and a rapid increase in drag and moment. ![]() ![]() The effects of plasma actuation on the airfoil’s flow field at both upward and downward stages were discussed at last.ĭynamic stall phenomenon widely exists on helicopter’s retreating blades and highly maneuverable aircraft. Compared with the steady actuation, unsteady actuation had more obvious advantages in dynamic stall control, with reducing the area of lift hysteresis loop by more than 30%. The flow control effect of dynamic stall was strongly dependent on the history of angle of attack. Both steady and unsteady actuation could effectively reduce the hysteresis loop area of the lift coefficients. The influence of actuation parameters on the airfoil’s lift and moment coefficients was studied. The effectiveness of alternating current (AC) DBD plasma actuation on reducing the area of lift hysteresis loop of the oscillating airfoil was verified through pressure measurements at a Reynolds number of 5.2 × 10 5. A DBD plasma actuator was adopted to control the dynamic stall of an oscillating CRA309 airfoil in this paper. At present, the control capability of dielectric barrier discharge (DBD) plasma actuation covers the flow velocity range of helicopter’s retreating blades, so it is necessary to extend it to the dynamic stall control of rotor airfoils.
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